dynarrc.segmentmethods.h

#define SEG_INSERT_POS_BEGIN	1
#define EMPTY_INDEX		0


// coordinates in the 2-D segment allocation
#define BANK_INDEX_FROM_SEG_INDEX(type, index)	\
	( ((unsigned int)(index)) >> LOGMAXSEG(type) )

#define BANK_FROM_SEG_INDEX(type, index)	\
	SEG_BANKS_ARR(type)[BANK_INDEX_FROM_SEG_INDEX(type, index)]
#define SLOT_FROM_SEG_INDEX(type, index)	\
	(((unsigned int)(index)) & MAXSEG_REMAINDER_BITMASK(type))

// pointer to the segment
#define PTR_SEG_FROM_INDEX(type, index)	\
	(BANK_FROM_SEG_INDEX(type, index) + SLOT_FROM_SEG_INDEX(type, index) )


#define SEG_ARR_SEG_NEXT_INDEX(type, value_seg) \
	(PTR_SEG_FROM_INDEX(type, (value_seg).index )->nextIndex)
// segment allocation/free/access
/* Accessor methods */
#define SEG_ARR_GET_SEG(type, segIndex)	\
	(	(segIndex)	!= EMPTY_INDEX && \
		(segIndex)  >= 0 && \
		(segIndex)	< SEG_INSERT_POS(type) )\
	? (	(TEMP_SEG_1(type)).index = (segIndex),\
		TEMP_SEG_1(type).nextIndex = \
			(int) (SEG_ARR_SEG_NEXT_INDEX(type, TEMP_SEG_1(type))),\
		TEMP_SEG_1(type))\
	: NULL_SEG(type)

#define SEG_ARR_SEG_FREE_SET(type, value_seg)	\
do{	\
		_SEG_ARR_FREE_LIST_ADD(type, value_seg ); \
		TOTAL_SEGS(type)--; \
		SEG_ARR_SEG_NEXT_INDEX(type, value_seg ) = EMPTY_INDEX; 	\
		(value_seg).index = (value_seg).nextIndex = EMPTY_INDEX	; \
}while(0);


// returns an available slot
// possibly recycled from a previously deleted segment
// returns NULL_SEG if alloc fails
static INLINE DYNARR_SEG_TYPE(DYNARR_DATA_TYPE) SEG_ARR_ALLOC_SEG_FUNC(DYNARR_DATA_TYPE)() {
	SEG_ARR_USE(DYNARR_DATA_TYPE);
	DYNARR_SEG_TYPE(DYNARR_DATA_TYPE) seg;

	// if there is a free segment available, take it
	_SEG_ARR_FREE_LIST_GRAB_INDEX(DYNARR_DATA_TYPE, seg);
	if (DYNARR_SEG_NOT_NULL(seg)){
		// valid seg
		TOTAL_SEGS(DYNARR_DATA_TYPE)++;
		return seg;
	}
	// no free segments available
	if (SEG_BANK_ALLOC_VIOLATION(DYNARR_DATA_TYPE)){
		/* Something bad happened */
		(TEMP_SEG_1(DYNARR_DATA_TYPE) = NULL_SEG(DYNARR_DATA_TYPE));
		return TEMP_SEG_1(DYNARR_DATA_TYPE);
	}
	else{
		/* do we need to allocate more banks? */
		if (SEG_INSERT_POS(DYNARR_DATA_TYPE) > SEG_BANK_INDEX_LIMIT_ARR(DYNARR_DATA_TYPE)[NUM_SEG_BANKS(DYNARR_DATA_TYPE) - 1]) {
			/* Yes: alloc a new bank */
			/* call function, and see return value */
			if (SEG_ARR_ALLOC_NEXT_FUNC(DYNARR_DATA_TYPE)() == 0){
				/* next-bank-allocation failed */
				SEG_BANK_ALLOC_VIOLATION(DYNARR_DATA_TYPE) = 1;
				printf("nFatal error: No more segment allocation possible."
					"ntSegment index: %d, Last possible index: %d "
					"NumSegBanks: %d, MaxSegBanks: %d "
					"ntFile: %sntLine: %dn",
					SEG_INSERT_POS(DYNARR_DATA_TYPE),
					SEG_BANK_INDEX_LIMIT_ARR(DYNARR_DATA_TYPE)[CURRENT_SEG_BANK(DYNARR_DATA_TYPE)],
					NUM_SEG_BANKS(DYNARR_DATA_TYPE),
					MAX_SEG_BANKS(DYNARR_DATA_TYPE),
					__FILE__, __LINE__);
				TEMP_SEG_1(DYNARR_DATA_TYPE) = NULL_SEG(DYNARR_DATA_TYPE);
			}
		}
		/* ready for insert, see if the coast is clear */
		if (SEG_BANK_ALLOC_VIOLATION(DYNARR_DATA_TYPE) == 0){
			/* insert a new segment in the current bank */
			TEMP_SEG_1(DYNARR_DATA_TYPE).index = SEG_INSERT_POS(DYNARR_DATA_TYPE);
			TEMP_SEG_1(DYNARR_DATA_TYPE).nextIndex = EMPTY_INDEX;
			SEG_INSERT_POS(DYNARR_DATA_TYPE)++;
			TOTAL_SEGS(DYNARR_DATA_TYPE)++;
		}
		/* finally, return*/
		return TEMP_SEG_1(DYNARR_DATA_TYPE);
	}
}